The present invention relates to a stable erythropoietin preparation and a process for formulating the same.
Erythropoietin is a circulating glycoprotein that stimulates the formation of red blood cells and is useful in the treatment or diagnosis of anemia. A single dose of erythropoietin is as small as a few micrograms and this level must be strictly observed. In other words, erythropoietin must be administered in the acurately measured trace amount in which it is formulated in a dosage form. However, erythropoietin is an instable substance and the compound purified to a clinically acceptable level and formulated in a trace amount (.perspectiveto.a few .mu.g) that is suitable for a single dosage will be easily inactivated by such environmental factors as temperature and humidity. It is therefore desired to formulate erythropoietin in a stabilized form.
As a result of various studies made in order to formulate a stable erythropoietin preparation, the present inventors found that this object can be attained by mixing erythropoietin with a particular compound. The present invention has been accomplished on the basis of this finding.